IMPROVING DAIRY FARM SUSTAINABILITY I - AN APPROACH TO ANIMAL AND CROP NUTRIENT MANAGEMENT PLANNING

This two-part article reports on a process for integrating knowledge t o develop and evaluate nutrient management plans for dairy farms. The focus is on accounting for and managing N, P, and K on a commercial fa rm. The case study farm was a well managed, progressive dairy farm loc ated in central New York with 320 lactating cows (Bos taurus), 290 hei fers, and 600 acres of crop land. This farm had the resources and mana gement skills that are a model for dairy farming in the future. Howeve r, mass nutrient balances indicated that 60 to 72% of imported N, P, a nd K were in excess of nutrient exports from the farm; 60 to 80% of th e imported nutrients were from purchased feeds. Evaluation and refinem ent of animal diets resulted in a reduction in crude protein content o f the rations by 2 percentage points while supporting a 13% increase i n milk production and a 34% decrease in total N excretion. Partial bud gets projected that ration reformulation increased net farm income by $40200. Implementation of a crop nutrient management plan was expected to decrease fertilizer purchases and application expenses by about $1 350, but construction of a remote manure storage pond and custom sprea ding of manure resulted in a decrease of net farm income of $4000. The vast quantity of data required and the complexity of the analysis ind icate that developing computerized decision aid tools will be necessar y to apply the process to a large number of farms.